the last time arafat was seen in public he flew to a paris hospital age 75 and sick. three weeks later he was dead. why? his wife refused an autopsy. rumors flew, aids murdered, poisoned, that's what many palestinians believed. >> all the circumstantial evidence, all the political evidence indicate only one direction, which is mr. sharon. >> reporter: israel denies it. there was no real evidence he had been killed, until this year. the investigation was triggered by swiss technicians working with al jazeera tv. they examined arafat's toothbrush and hat and found traces of radioactive polonium 210. ten times more toxic than cyanide. the question now is, will they find it on his bones? >> the likelihood of being able to detect polonium 210 this long after contamination i think is very low. >> reporter: in that case, how did they find it on his clothes? the tests could raise more questions than it answers. yasser arafat, controversial in life, his death still a riddle. martin fletcher, nbc news, ramallah, the west bank. >>> in this country and parts of this area in fact,